Wimbledon: A look at day two

Serena Williams of the United States returns the ball to Mandy Minella of Luxembourg during their Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Serena Williams of the United States reacts as she plays Mandy Minella of Luxembourg in a Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Serena Williams of the United States is shielded from the sun during a change of ends break as she plays Mandy Minella of Luxembourg in a Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Laura Robson of Britain reacts after defeating Maria Kirilenko of Russia in their Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Anja Niedringhaus)

Novak Djokovic of Serbia serves to Florian Mayer of Germany in their Men's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Novak Djokovic of Serbia gestures after slipping against Florian Mayer of Germany in their Men's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

David Ferrer of Spain reacts after slipping on the court during his Men's first round singles match against Martin Alund of Argentina at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Agnieszka Radwanska of Poland plays a return to Yvonne Meusburger of Austria during their Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Kirsty Wigglesworth)

Serena Williams of the United States reacts as she plays Mandy Minella of Luxembourg in a Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Novak Djokovic of Serbia returns the ball to Florian Mayer of Germany during a Men's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Sam Querrey of the United States plays a return to Bernard Tomic of Australia during their Men's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Alastair Grant)

Richard Gasquet of France, left, reacts during his Men's first round singles match against Marcel Granollers of Spain at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Kirsty Wigglesworth)

David Ferrer of Spain gestures to the public after defeating Martin Alund of Argentina in their Men's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Laura Robson of Britain, right, shakes hands with Maria Kirilenko of Russia after defeating her in their Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Anja Niedringhaus)

Novak Djokovic of Serbia reacts after defeating Florian Mayer of Germany in their Men's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Kimiko Date-Krumm of Japan serves to Carina Witthoeft of Germany during their Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Kirsty Wigglesworth)

Serena Williams of the United States plays a return during her Women's first round singles match against Mandy Minella of Luxembourg at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)

Serena Williams of the United States serves to Mandy Minella of Luxembourg during their Women's first round singles match at the All England Lawn Tennis Championships in Wimbledon, London, Tuesday, June 25, 2013. (AP Photo/Sang Tan)